In many applications, lubricant, such as oil, is used to lubricate moving components such as gears. It often is desirable to control the level of oil within a gear housing or case surrounding tee lubricated components. The level or amount of lubricant in the housing is important and, sometimes critical. Lubricant may have to be periodically or continuously replenished. Or, the volume of lubricant may simply vary during use.
For instance, when the ambient temperature surrounding lubricated components varies significantly, this temperature variation can cause significant expansion of the lubricating oil, causing lubricant management problems because of the varying volume of oil within the lubricating system. It is desirable to regulate the lubricant level within specified containment of lubricated components notwithstanding significant changes in lubricant volume, such as that caused by temperature variations.
Many lubricating systems also incorporate a deaerating system somewhere in the system whereby air entrapped in the lubricating liquid, such as oil, is separated. There are a variety of deaerating devices, but the most common is a centrifugal deaerating device which separates the heavier oil from the lighter air by centrifugal action, such as by a rotating chamber having a radially outwardly disposed liquid outlet.
In order to manage the lubricant level in systems of the character described above, some sort of means must be employed to drain excess lubricant from the cavity surrounding the lubricated components and transport the excess lubricant to a reservoir, for instance, where it might be stored until it is needed to be resupplied to the cavity when the lubricant level drops below a preselected level.
This invention is directed to a novel concept of utilizing the oil level in a centrifugal deaerator as a signal to divert, or add, liquid from the working circuit of the operative components to maintain an appropriate working lubricant level around the components. This approach eliminates any variety of additional devices, and the deaerator itself is used to signal and/or sense the need for or excess of lubricant in the system.